我正在使用Jdbctemplate从db中检索Bean.这是我的方法.
public List<trackerv3Livedata> getTrackerData() {
return List<trackerv3Livedata> live = (List<trackerv3Livedata>) jdbcTemplate.queryForList("select * from mmitrackerv3_livedata where accountid =?",new Object[]{aid},trackerv3Livedata.class);
}
并且trackerv3Livedata bean结构正在跟随
public class trackerv3Livedata implements Serializable {
/**
*
*/
private static final long serialVersionUID = 2409168269491619888L;
private int deviceid;
private Long timestamp;
private Mmitrackerv3Device mmitrackerv3Device;
private Mmitrackerv3Account mmitrackerv3Account;
private double latitude;
private double longitude;
private Double altitude;
private Double speedkph;
private Double heading;
private Double gpssignal;
private Integer geozoneid;
private Double distancekm;
private Double gsmsignal;
private Double mainpower;
private Integer laststatustime;
private Double internalbattry;
private Double temperature;
private Short dinput1;
private Short dinput2;
private Short dinput3;
private Short dinput4;
private Short dinput5;
private Short dinput6;
private Short dinput7;
private Short dinput8;
private Short ainput1;
private Short ainput2;
private Short ainput3;
private Short ainput4;
private Short doutput1;
private Short doutput2;
private Short doutput3;
private Short doutput4;
/* There are Some Getter And Setter Method With Constructor */
}
在我的方案中,完全可能不会得到我的查询,所以我的问题是如何解决以下错误消息.
org.springframework.jdbc.IncorrectResultSetColumnCountException: Incorrect column count: expected 1,actual 38
在我看来,我应该回到null而不是抛出异常.我怎样才能解决这个问题？提前致谢.
解决方法
发生这种情况是因为您使用的queryForList方法不支持多列.从JdbcTemplate查看queryForList的实现
public <T> List<T> More ...queryForList(String sql,Object[] args,Class<T> elementType) throws DataAccessException
{
return query(sql,args,getSingleColumnRowMapper(elementType));
}
getsingleColumnRowMapper()方法创建一个新的RowMapper,用于从单个列读取结果对象.
您可以使用下面给出的方法.
public <T> List<T> query(String sql,RowMapper<T> rowMapper) throws DataAccessException
{
return query(sql,new RowMapperResultSetExtractor<T>(rowMapper));
}